The invention relates to a heating device operated by means of liquid fuel, and specifically to a vehicle heating device which has a vaporization burner comprising an absorbent body, which can be acted upon by a liquid fuel, and which has at least one surface facing a combustion chamber of the heating device.
German Patent No. 3,233,321 and corresponding U.S. Pat. No. 4,530,658 show a heating device, specifically, a motor vehicle heating device, having a vaporization burner of the kind described above. The absorbent body is formed, for instance, by a fleece. It is the function of the absorbent body to vaporize the fuel and in combination with correspondingly directed combustion air, to produce a combustible mixture which is burned in a combustion chamber of the heating device with concurrent flame formation. Past experience has shown that local overheating may occur on the surface of the absorbent body that faces the combustion chamber with adverse effects to the absorbent body, resulting in a reduced service life thereof. Moreover, the fuel absorbed by .the absorbent body has a chemically damaging effect, and the exhaust gases resulting from the combustion process further contribute towards deterioration of the absorbent body.
U.S. Pat. No. 4,459,805 discloses a burner device for the regeneration of an exhaust filter system, especially in connection with Diesel automotive engines, in which a mixture of fuel and combustion air is treated by way of a vaporizer in a mixing chamber. The preliminary mixture thus prepared is introduced into the combustion chamber via nozzles formed by holes. These holes acting as nozzles are relatively large and are disposed in a flame holding plate.